  & \multicolumn{1}{P{1.2in}}{Control mean: call only} & \multicolumn{2}{P{2in}}{ATE: effect of getting asked IVR question vs. call only}\\
  & \multicolumn{1}{P{1.2in}}{\{H1\}} & \multicolumn{2}{P{2in}}{\{H2\} vs. \{H1\}}\\
\cmidrule(lr){2-2} \cmidrule(lr){3-4}
Outcome & \multicolumn{1}{c}{$\mu$} & \multicolumn{1}{c}{$\tau$} & \multicolumn{1}{c}{N}\\
\midrule
Answered follow-up phone call (0/1) & 0.787 & 0.036^{*} & 3718\\
 & (0.410) & (0.015) & \\
 & & & \\
